<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>策略模式</title>
</head>
<body>
	<div id="qqqqq">11111</div>
	<div id="wwwww">11111</div>
	<div>11111</div>
	<div>11111</div>
	<div>11111</div>
	<div>11111</div>
</body>
<script type="text/javascript">
	try {
		// statements
		alert(document.body.contains(11111))
	} catch(e) {
		// statements
		console.log(e);
	}
	try {
		console.log(document.body.contains(document.getElementById('qqqqq')))
		// statements
	} catch(e) {
		// statements
		console.log(e);
	}
	console.log(document.body.contains(document.getElementById('sss')))
	// alert(document.body.contains(document.getElementsByTagName('div')))
	// console.log(document.body.contains(document.getElementsByTagName('div')[0]))
	// alert(document.body.contains("11111"))
	var perrmS = function(salary){
		return salary*4
	}

	var cacular = function(fn){
		return perrmS()
	}
</script>
</html>